In message , Dave
Wheeler writes
I doubt the Shetlands have recorded a temperature that high since
their
records began! 
Warmest ever on Fair Isle is 20.2C (1975) while at Lerwick it is 23.
3C (1982), though there was an unofficial 27.8C reported from
Sumburgh Head Lighthouse back in 1910.
Presumably someone left the thermometer next to the lighthouse light.

--
Paul Hyett (change 'invalid83261' to 'blueyonder' to email me)